1189251Ssam/* 2189251Ssam * MD5 hash implementation and interface functions 3189251Ssam * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 4189251Ssam * 5252726Srpaulo * This software may be distributed under the terms of the BSD license. 6252726Srpaulo * See README for more details. 7189251Ssam */ 8189251Ssam 9189251Ssam#include "includes.h" 10189251Ssam 11189251Ssam#include "common.h" 12189251Ssam#include "md5.h" 13189251Ssam#include "crypto.h" 14189251Ssam 15189251Ssam 16189251Ssam/** 17189251Ssam * hmac_md5_vector - HMAC-MD5 over data vector (RFC 2104) 18189251Ssam * @key: Key for HMAC operations 19189251Ssam * @key_len: Length of the key in bytes 20189251Ssam * @num_elem: Number of elements in the data vector 21189251Ssam * @addr: Pointers to the data areas 22189251Ssam * @len: Lengths of the data blocks 23189251Ssam * @mac: Buffer for the hash (16 bytes) 24214734Srpaulo * Returns: 0 on success, -1 on failure 25189251Ssam */ 26214734Srpauloint hmac_md5_vector(const u8 *key, size_t key_len, size_t num_elem, 27214734Srpaulo const u8 *addr[], const size_t *len, u8 *mac) 28189251Ssam{ 29189251Ssam u8 k_pad[64]; /* padding - key XORd with ipad/opad */ 30189251Ssam u8 tk[16]; 31189251Ssam const u8 *_addr[6]; 32189251Ssam size_t i, _len[6]; 33281806Srpaulo int res; 34189251Ssam 35189251Ssam if (num_elem > 5) { 36189251Ssam /* 37189251Ssam * Fixed limit on the number of fragments to avoid having to 38189251Ssam * allocate memory (which could fail). 39189251Ssam */ 40214734Srpaulo return -1; 41189251Ssam } 42189251Ssam 43189251Ssam /* if key is longer than 64 bytes reset it to key = MD5(key) */ 44189251Ssam if (key_len > 64) { 45214734Srpaulo if (md5_vector(1, &key, &key_len, tk)) 46214734Srpaulo return -1; 47189251Ssam key = tk; 48189251Ssam key_len = 16; 49189251Ssam } 50189251Ssam 51189251Ssam /* the HMAC_MD5 transform looks like: 52189251Ssam * 53189251Ssam * MD5(K XOR opad, MD5(K XOR ipad, text)) 54189251Ssam * 55189251Ssam * where K is an n byte key 56189251Ssam * ipad is the byte 0x36 repeated 64 times 57189251Ssam * opad is the byte 0x5c repeated 64 times 58189251Ssam * and text is the data being protected */ 59189251Ssam 60189251Ssam /* start out by storing key in ipad */ 61189251Ssam os_memset(k_pad, 0, sizeof(k_pad)); 62189251Ssam os_memcpy(k_pad, key, key_len); 63189251Ssam 64189251Ssam /* XOR key with ipad values */ 65189251Ssam for (i = 0; i < 64; i++) 66189251Ssam k_pad[i] ^= 0x36; 67189251Ssam 68189251Ssam /* perform inner MD5 */ 69189251Ssam _addr[0] = k_pad; 70189251Ssam _len[0] = 64; 71189251Ssam for (i = 0; i < num_elem; i++) { 72189251Ssam _addr[i + 1] = addr[i]; 73189251Ssam _len[i + 1] = len[i]; 74189251Ssam } 75214734Srpaulo if (md5_vector(1 + num_elem, _addr, _len, mac)) 76214734Srpaulo return -1; 77189251Ssam 78189251Ssam os_memset(k_pad, 0, sizeof(k_pad)); 79189251Ssam os_memcpy(k_pad, key, key_len); 80189251Ssam /* XOR key with opad values */ 81189251Ssam for (i = 0; i < 64; i++) 82189251Ssam k_pad[i] ^= 0x5c; 83189251Ssam 84189251Ssam /* perform outer MD5 */ 85189251Ssam _addr[0] = k_pad; 86189251Ssam _len[0] = 64; 87189251Ssam _addr[1] = mac; 88189251Ssam _len[1] = MD5_MAC_LEN; 89281806Srpaulo res = md5_vector(2, _addr, _len, mac); 90281806Srpaulo os_memset(k_pad, 0, sizeof(k_pad)); 91281806Srpaulo os_memset(tk, 0, sizeof(tk)); 92281806Srpaulo return res; 93189251Ssam} 94189251Ssam 95189251Ssam 96189251Ssam/** 97189251Ssam * hmac_md5 - HMAC-MD5 over data buffer (RFC 2104) 98189251Ssam * @key: Key for HMAC operations 99189251Ssam * @key_len: Length of the key in bytes 100189251Ssam * @data: Pointers to the data area 101189251Ssam * @data_len: Length of the data area 102189251Ssam * @mac: Buffer for the hash (16 bytes) 103214734Srpaulo * Returns: 0 on success, -1 on failure 104189251Ssam */ 105214734Srpauloint hmac_md5(const u8 *key, size_t key_len, const u8 *data, size_t data_len, 106189251Ssam u8 *mac) 107189251Ssam{ 108214734Srpaulo return hmac_md5_vector(key, key_len, 1, &data, &data_len, mac); 109189251Ssam} 110